Execution contexts closing in to being enabled by default is a big one. As is the io_uring based event loop that is also finally getting merged (even though that one is also hidden behind flags).

So the execution model is now even more similar to Go's one, with the M:N scheduling, IIUC?

I much like to hear that, as I found Crystal to provide pretty much exactly the same concurrency primitives as Go, but with a much nicer syntax, as I compared here:

https://livesys.se/posts/crystal-concurrency-easier-syntax-t...